As Wednesday's debate made vividly clear, there are almost as many versions of "Medicare for All" as there are Democratic candidates — and each one thinks their plan is the path to insuring every American.

For Sen. Kamala Harris of California and former Vice President Joe Biden, health care became the sequel to their first fiery exchange — when Harris, peering over at Biden, movingly recalled during the first round of debates last month how the busing policy he once backed had changed the course of her life.

This time they were in Detroit, joined for the second night of this second round of Democratic primary debates by Sen. Cory Booker of New Jersey and seven other presidential hopefuls.

Though only two candidates referenced health care in their opening remarks — former Housing and Urban Development Secretary Julian Castro, who also served as mayor of San Antonio, Texas, and Sen. Kirsten Gillibrand of New York — there was another elephant in the room: Medicare for All.

For about 24 minutes, nearly a quarter of the debate, the 10 Democrats wrestled for control of the health care issue. They batted around arguments for why their version of a government plan would bring Americans universal health coverage. They cited the hefty profits of the insurance and pharmaceutical industries as a critical symptom of the system's ills.

Harris was confident in outlining her Medicare for All plan, saying she had listened to Americans to create an approach that would respond to their needs. This would include a public option and a 10-year transition to a new Medicare-based system.

But Biden quickly hit back, saying that when someone promises something in 10 years, you have to wonder why it will take so long. He reiterated his support for the Affordable Care Act, saying it is working and the best way forward is to "build on what's working."

They bickered over how to retain choices for consumers, using terms like private and employer-based insurance, public option and Medicare Advantage.

At times the back and forth was fast and furious, and it seemed even the candidates were lost in the numbers they were firing across the stage. Fortunately, we were taking notes.

HARRIS: "I'm going to go back to Vice President Biden because your plan does not cover everyone in America by your staff's and your own definition. Ten million people, as many as 10 million people, will not have access to health care."

Her claim needs, at least, further scrutiny.

When Biden unveiled his health care plan a couple of weeks ago, his campaign noted — under the bold heading "Give Every American Access to Affordable Health Insurance" — that it would insure "more than an estimated 97 percent of Americans."

Sen. Bernie Sanders of Vermont, also running for the Democratic presidential nomination, first proposed the Medicare for All plan. His campaign initially seized on that figure Monday, arguing that would leave about 10 million people uninsured.

Imprecise math aside, other factors could play into the number of uninsured individuals under a Biden health care system. That includes the fact that some Americans just don't want insurance — the problem the Affordable Care Act's individual mandate was intended to fix. But Republicans in Congress repealed the penalty for that mandate.

SEN. MICHAEL BENNET: "I believe we should finish the job we started with the Affordable Care Act with a public option that gives everybody in this audience the chance to pick for their family whether they want private insurance or public insurance and requires drug companies to be negotiated with by Medicare and it provides competition. That is totally different from the plan that Sen. Warren and Sen. Sanders and Sen. Harris have proposed, which would make illegal employer-based health insurance in this country."

Both Bennet, of Colorado, and Biden claimed Harris' plan would lead to the elimination of employer-based insurance. That could be the case, particularly for plans that would not meet the expansive requirements for coverage of "medically necessary" services Harris outlined.

But there is more to learn about Harris' plan, released just two days ago — and at least a couple of problems with Bennet's claim.

To start, while Warren, Sanders and Harris all use the term "Medicare for All" to refer to their preferred health care plan, they do not share a single plan.

The Sanders plan (endorsed by Warren) would eliminate private insurance in favor of a government plan. Harris' plan, though, keeps a role for private insurers willing to offer Medicare coverage that meet certain benefit and cost requirements.

During her plan's decadelong phase-in, Harris wrote in a Medium post — and Bennet's campaign cited as evidence — that it would "provide a commonsense path for employers, employees, the underinsured, and others on federally-designated programs, such as Medicaid or the Affordable Care Act exchanges, to transition."

Would those employer plans transition out of existence? Harris' campaign did not immediately respond to inquiries about the future of employer-based insurance under her proposal.

Kaiser Health News is a nonprofit news service covering health issues. It is an editorially independent program of the Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.